In Lynch syndrome (hereditary non-polyposis colorectal cancer), the MMR gene mutation most commonly associated with extracolonic endometrial and ovarian cancers at a higher rate than the others is:

• A MSH6 ✓
• B MLH1
• C MSH2
• D PMS2

Explanation

MSH6 mutations in Lynch syndrome are disproportionately associated with endometrial cancer (lifetime risk ~40–60%) and to a lesser extent ovarian cancer, while colorectal cancer risk is lower and age of onset is later than MLH1 or MSH2. MLH1 and MSH2 mutations carry the highest lifetime colorectal cancer risk (~50–70%). PMS2 mutations confer relatively attenuated phenotypes. This distinction is important for gynaecological surveillance planning.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.